Magnetoelectric effect probe through ppm Fe doping in BaTiO3

• Low Fe contamination as the main source of ferromagnetism on BaTiO3.
• Magnetoelectric effect induced by the BaTiO3 transitions in the Fe rich phase.
• Magnetization measurements can complement BaTiO3 compounds characterization.

The nominal BaTiO3 compound often exhibits an assortment of controversial magnetic signals which can be simply explained through minute presence of spurious magnetic elements in the perovskite matrix, even when this compound is synthesized from high grade Ba and Ti precursors. Proton Induced X-Ray Emission (PIXE) technique enable to confirm ∼100 ppm of Fe contaminant which masks the utterly BaTiO3 diamagnetism. Nevertheless, besides the expected paramagnetism of highly diluted Fe ions, it is also possible to observe a cooperative magnetic moment signature which exhibits an intricate relation with the phase transitions of the BaTiO3 matrix. Such magneto-electric coupling signature is further corroborated by Raman spectroscopy, dielectric and X-ray diffraction measurements, indicating to a partial segregation of a rich Fe oxide phase, having a local structure clamped to the perovskite crystallites, hence acting as a practical probe sensitive to the local structural transitions of the host material.